Rhodes Dell L
Department of Psychology, Reed College, Portland, Ore. 97202 U.S.A.
Pain. 1979 Aug;7(1):51-63. doi: 10.1016/0304-3959(79)90106-4.
Three areas within the periventricular system were studied: caudal periaqueductal gray (PAG), rostral PAG, and caudal midline thalamus. Rats were chronically prepared with a bipolar stimulating electrode in one of these areas and two lesion electrodes in another. Current thresholds for stimulation-produced analgesia in the tail-flick test were assessed. Then, lesions were made and thresholds for analgesia re-assessed. Destruction of the caudal PAG consistently produced large increases in thresholds for analgesia at rostral stimulation sites; however, destruction of the rostral areas did not affect thresholds at caudal PAG sites. Lesions in all 3 areas yielded significant reductions in baseline (pre-brain stimulation) tail-flick latencies. Both sham lesioned control animals and animals with small lesions maintained stable baseline latencies and analgesia thresholds. The data support the view that all 3 brain areas studied contribute to the same pain-inhibitory system. They further suggest that stimulation at rostral sites activates elements which connect to or pass through the caudal PAG.
导水管周围灰质尾部（PAG）、导水管周围灰质头部和丘脑尾侧中线。大鼠被长期植入，在这些区域之一放置一个双极刺激电极，在另一个区域放置两个损伤电极。评估甩尾试验中刺激产生镇痛的电流阈值。然后进行损伤，并重新评估镇痛阈值。破坏导水管周围灰质尾部在头部刺激部位持续产生镇痛阈值的大幅升高；然而，破坏头部区域并不影响导水管周围灰质尾部部位的阈值。所有三个区域的损伤均使基线（脑刺激前）甩尾潜伏期显著缩短。假损伤对照动物和小损伤动物均保持稳定的基线潜伏期和镇痛阈值。数据支持这样的观点，即所研究的所有三个脑区都对同一个疼痛抑制系统有贡献。它们进一步表明，在头部部位的刺激激活了与导水管周围灰质尾部相连或穿过该区域的元件。
